Effect of timing of insemination on conception rate in local and cross bred cattle (adult cow) in Bannu and Wana (S. Waziristan Agency) [Pakistan]

A total 120 local breed cows were inseminated with frozen semen. Among these 60 cows were inseminated with single insemination, while 60 cows were inseminated twice in same oestrus period with interval of 6 hours. All these cows were checked for pregnancy by rectal palpation method. Among these cows 30 cows were injected with progesterone 50mg i/m one minute after insemination. The conception rate in control group is 43.33% and treated group 46.66% in single insemination while in double insemination 60% in control group and 63.33% in progesterone treated group respectively. It is concluded that double insemination with frozen semen in local cows increase conception rate, while the conception rate is also improved by progesterone treatment in single and double insemination in local breed cows. In crossbred 120 cows were inseminated with frozen semen. Among these 60 cows were inseminated single insemination and 60 cows were inseminated twice in same oestrus after 6 hours of interval. Traced all cows and checked for pregnancy by rectal palpation method. Among these in each group 30 cows were injected with progesterone 50mg i/m one minute after insemination. The conception rate is 50% in control group and 46.66% in progesterone treated group in single insemination, while 53.33% in control group and 60% in progesterone treated group in double insemination. It concluded that the use of exogenous progesterone in single insemination cross bred cows may adversely effect the hormonal profile and ovulation, while in double insemination exogenous progesterone was administered at the end of, oestrous, effect the conception rate favorably. A total 12 semen samples, each consisting of two consecutive ejaculates, collected from one bull of Holstein-Friesian breed. The semen was extended in lactose, fructose egg yolk, and glycerol extender. Semen packed in 0.5 ml french straws was frozen and stored in liquid nitrogen. Thawing was carried out in hot water at 35 degree C for 20 second.